Mobile communication devices may include a variety of components including circuit boards, integrated circuit (IC) devices and/or System-on-Chip (SoC) devices. The components may include processing devices, user interface components, storage and other peripheral components that communicate through a shared data communication bus, which may include a serial bus or a parallel bus. General-purpose serial interfaces known in the industry, including the Inter-Integrated Circuit (I2C or I2C) serial bus and its derivatives and alternatives, including interfaces defined by the Mobile Industry Processor Interface (MIPI) Alliance, such as the I3C interface, the system power management interface (SPMI), and the Radio Frequency Front-End (RFFE) interface.
In one example, the I2C serial bus is a serial single-ended computer bus that was intended for use in connecting low-speed peripherals to a processor. Some interfaces provide multi-master busses in which two or more devices can serve as a bus master for different messages transmitted on the serial bus. In another example, the RFFE interface defines a communication interface for controlling various radio frequency (RF) front-end devices, including power amplifier (PA), low-noise amplifiers (LNAs), antenna tuners, filters, sensors, power management devices, switches, etc. These devices may be collocated in a single integrated circuit (IC) device, or provided in multiple IC devices. In a mobile communications device, multiple antennas and radio transceivers may support multiple concurrent RF links.
Systems with a multi-drop serial bus may require interconnected devices to be able to communicate with each other in a consistent manner such that a message/datagram from one device can be sent to one or more other devices on the serial bus concurrently while the one or more other receiving devices need to know the originator of the message/datagram. As the devices on such multi-drop buses use a common limited protocol to exchange messages, embedding source/sender identifier bits to identify the originator is expensive in terms of resources, power, and latency. Therefore, there is a need for an efficient way to convey sender identity over a multi-drop bus.